In the baking industry, products such as bread loaves, rolls and the like are produced in huge numbers. In general the processes of the baking industry are highly automated and mechanized, so that the huge volume of products can be produced and handled at reasonable cost.
One area of baking industry that has stubbornly resisted attempts to achieve effective automation is the handling of the packaged products. Notwithstanding substantial efforts to automate this aspect of bakery production, cost effective automation has been very elusive and the loading of packaged products has remained a highly labor intensive, and therefore costly phase of the operation.
In the production of bread and rolls, for example, it is typical practice to package many of the baked products in plastic bags. In the case of bread, a single loaf per bag is typical, while for rolls there may be a number of items per bag. The bagged products are then loaded into special low-sided shipping baskets or onto pallet trays. Typically, basket are formed of plastic material and are arranged to be self-stacking, when loaded with product, and at least partially nesting when empty. The trays typically are relatively flat and are designed to be stored and carried in racks when filled with product, so that the bakery products, which are typically quite soft, are not subjected to weight loading during storage and transportation. That is, in a vertical stack of loaded baskets, the weight of a loaded shipping basket is supported by the basket below. When using trays, loaded trays are support by the structure of a rack. For the purposes of this application, the term "basket" will be understood to refer generically to baskets, trays, or the like, unless the context indicates otherwise.
In the loading of the shipping baskets, several objectives must be observed. In general, it is desired to load as many product items into a basket as practicable, without excessively compressing the product. This typically involves a special pattern loading of the basket, with a certain number of product packages oriented in one direction and other packages oriented in another direction, etc. Thus each product type has an optimum loading pattern which must be followed. Additionally, it is necessary that each shipping basket loaded with products of the same type be loaded with an equal number of items. And finally, end-for-end orientation of the product packages is frequently important as where the product is contained in plastic bags with "tails".
In the bagging of bakery products, it is customary for the open end of a filled bag to be closed and tied by a clip or twist wire. This leaves a "tail" projecting from one end of the package. Bakers strongly prefer to orient the packages in the shipping baskets so that these tails are not positioned adjacent the side walls of the basket. The sidewalls of the baskets usually are very low, so that the package tails would be exposed, being both somewhat unsightly and also subject to being snagged. Accordingly, the consistent practice of the industry in the basket loading of packaged products is to orient the package tails to extend inwardly, away from the basket walls.
In a typical industrial bakery operation, the products being handled at the basket loading section are frequently changed, so that the various loading requirements mentioned above, i.e., number of packages, loading pattern, and tail orientation, are constantly changing. As a result, and notwithstanding a generally high degree of automation elsewhere through the baking operations, the basket loading tasks continue to be performed largely manually, in an arduous, labor intensive, and therefore costly manner.
Pursuant to the invention, however, a system is provided which enables the basket loading operations to be automated to a high degree, such that a wide variety of product types can be loaded into shipping baskets an a manner consistent with all of the objectives discussed above and at consistently high production rates. The improved system greatly reduces the labor requirements of the loading operation and permits more effective reassignment of the workers now designated for this task.
In accordance with one aspect of the invention, a novel and improved basket loading arrangement is provided which utilizes a conveyor system, for supplying empty shipping baskets to each of a plurality of load stations. A product conveyor system, for feeding product packages to a loading position adjacent the basket conveyor system, is provided at each load station. A programmable robotic loader is also located at load station. The loader includes a gripper mechanism which is both controllable through a main operating program and is also easily reconfigurable if necessary to accommodate major changes in product types. Each product conveyor system delivers product packages on a continuous basis and in a predetermined orientation, to a loading position. When a predetermined number of packages, forming a product group, is gathered at the loading position, the robotic loader grips the entire group and transfers it to a shipping basket held at a loading position on the basket conveyor system. By means of a pre-established program, determined for the specific product packages being handled at the time, the robotic loader executes a plurality of loading operations, in each case making a pick-up of a predetermined load group and placing the group in a specific predetermined pattern location in the basket. Where the product is packaged in bags with tails, the package placement is carried out with a predetermined orientation of the package tails. Upon a change of product type, the robotic loader is operated under a different tut pre-established program, perhaps with a load group of different number and with a different number and orientation of placements in the waiting shipping basket. In some cases, the gripper may have to be reconfigured, or the robotic loader may have to be fitted with an alternate gripper mechanism, preset for a specific new product type.
In accordance with another aspect cf the invention, an advantageous form of basket conveyor system is provided, which includes a primary conveyor for supplying empty shipping baskets to a plurality of load stations and a plurality of secondary conveyor sections, one for each load station. In conjunction with each secondary conveyor section there is a mechanism for selectively diverting baskets from the primary conveyor in accordance with demand. Desirably the principal conveyor mechanisms for both primary and secondary conveyors are slip conveyors, which are maintained in continuous operation. When baskets are held against movement, as for loading with product packages or for the diverting of baskets to a secondary conveyor section, the endless conveyor elements continue in motion and slip underneath the empty baskets.
A particularly advantageous form of means for diverting empty baskets to the secondary conveyor sections is a lift mechanism which straddles the line of the primary basket conveyor and includes a high friction belt conveyor section interposed between continuing sections of the primary conveyor. Lift elements at each side of the belt conveyor are adapted to engage the side edges of a basket and elevate the basket to the level of a secondary conveyor section. A pusher mechanism at the elevated level displaces the basket onto the surface of a secondary conveyor, which advances the basket toward a loading position. When a demand for an empty basket is signalled, the belt conveyor is stopped momentarily with a basket in proper position for lifting to the level of the secondary conveyor. While the belt conveyor is stopped, its high friction characteristics serve temporarily to hold up any upstream baskets being advanced by the primary conveyor. As soon as the basket has been lifted from the belt conveyor, its operation, and the continuing flow of empty baskets along the primary conveyor, is resumed. The primary conveyor is, of course, operated at sufficient speed to enable it to supply baskets to a plurality of load stations.
In accordance with another aspect of the invention, a novel form of product supply conveyor is provided, which enables the soft bakery products to be delivered to a loading position and collected in predetermined load groups, to be successively picked up by the robotic loader. The product conveyor is a free-roller type of conveyor, in itself known, in which the conveyor surface is made up of closely spaced rollers supported for free rotation on individual shafts. The shafts are carried by spaced conveyor chairs. The soft bakery products placed on the conveyor are advanced successively toward the loading position. A stop element engages the first package of a group, and the others stack up behind as the roller elements of the conveyor roll underneath the stopped packages. When a complete load group has been delivered to the loading position, indicated by signals from photocells or other sensor devices, a brake element engages the upper surfaces of the rollers in the region of the load group, forcing the rollers to reverse rotate so that the forwardly advancing rollers impart no forward pressure to the collected package load group. This avoids any crushing of the soft bakery products by residual forward pressure resulting from friction of the rollers, as the product conveyor continues to operate while the load group is waiting to be picked up by the robotic loader.
A still further feature of the invention is the provision of a novel and improved form of product gripping mechanism, adapted for the pickup of a complete load group of packages and the placement thereof in a shipping basket. The gripping mechanism includes a frame on which are supported a plurality of downwardly projecting soft suction devices. The suction devices can be movably positioned for optimum placement with respect to the several packages of a load group and are selectively actuated in accordance with operations of the robotic loader. To advantage, the gripper mechanism includes pivoting side retainers for lateral confinement of the product packages during rotary and translational movements of the gripper during transfer of the packages from the load position on the product conveyor to the shipping basket being loaded. The side retainers may also serve to compress the soft product laterally as necessary to accommodate its placement in the waiting basket.
For a more complete understanding of the above and other features and advantages of the invention, reference should be made to the following detailed description of a preferred embodiment of the invention and to the accompanying drawings.